From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79503154B2; Tue, 2 Jan 2024 17:11:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="HKg8KNPo" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1704215480; bh=AFTu4kCVpQW+240gbyhTAzKqckFwaJgY5sujDYN2wQg=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References:From; b=HKg8KNPotu2WM69XIQDhpzv2cWDap3cUZNf2ZnMbi7HFlvZQlQVTJrlFjk9RX65XO LS4L1FbMtSckIMtW8VaBLzFoXd6/lGhWQLDNbV5OiRblnm3yzr9YQIhpIUdh/SOWzn 5NzG3LExeXNaP5Fc2RHfeQBSRSR5SsE65E3Nj1DA= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id DA3191286828; Tue, 2 Jan 2024 12:11:20 -0500 (EST) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 3wtclUnreVKD; Tue, 2 Jan 2024 12:11:20 -0500 (EST) Received: from lingrow.int.hansenpartnership.com (unknown [153.66.160.227]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 35B781286813; Tue, 2 Jan 2024 12:11:19 -0500 (EST) From: James Bottomley To: linux-integrity@vger.kernel.org Cc: Jarkko Sakkinen , keyrings@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v6 10/20] tpm: add buffer function to point to returned parameters Date: Tue, 2 Jan 2024 12:03:58 -0500 Message-Id: <20240102170408.21969-11-James.Bottomley@HansenPartnership.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240102170408.21969-1-James.Bottomley@HansenPartnership.com> References: <20240102170408.21969-1-James.Bottomley@HansenPartnership.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Replace all instances of &buf.data[TPM_HEADER_SIZE] with a new function tpm_buf_parameters() because encryption sessions change where the return parameters are located in the buffer since if a return session is present they're 4 bytes beyond the header with those 4 bytes giving the parameter length. If there is no return session, then they're in the usual place immediately after the header. Signed-off-by: James Bottomley Reviewed-by: Stefan Berger --- v4: add kdoc v5: update kdoc add review --- drivers/char/tpm/tpm-buf.c | 28 ++++++++++++++++++++++++++++ include/linux/tpm.h | 2 ++ 2 files changed, 30 insertions(+) diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c index 32619e9ab4fa..bb81180495d1 100644 --- a/drivers/char/tpm/tpm-buf.c +++ b/drivers/char/tpm/tpm-buf.c @@ -220,3 +220,31 @@ u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset) return be32_to_cpu(value); } EXPORT_SYMBOL_GPL(tpm_buf_read_u32); + +static u16 tpm_buf_tag(struct tpm_buf *buf) +{ + struct tpm_header *head = (struct tpm_header *)buf->data; + + return be16_to_cpu(head->tag); +} + +/** + * tpm_buf_parameters - return the TPM response parameters area of the tpm_buf + * @buf: tpm_buf to use + * + * Where the parameters are located depends on the tag of a TPM + * command (it's immediately after the header for TPM_ST_NO_SESSIONS + * or 4 bytes after for TPM_ST_SESSIONS). Evaluate this and return a + * pointer to the first byte of the parameters area. + * + * @return: pointer to parameters area + */ +u8 *tpm_buf_parameters(struct tpm_buf *buf) +{ + int offset = TPM_HEADER_SIZE; + + if (tpm_buf_tag(buf) == TPM2_ST_SESSIONS) + offset += 4; + + return &buf->data[offset]; +} diff --git a/include/linux/tpm.h b/include/linux/tpm.h index e8172f81c562..6be263509e81 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -344,6 +344,8 @@ u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset); u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset); u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset); +u8 *tpm_buf_parameters(struct tpm_buf *buf); + /* * Check if TPM device is in the firmware upgrade mode. */ -- 2.35.3